The water main took about 10 to 12 hours to repair. On Monday, a City of Ottawa spokesperson said repairs to the road would take longer. The city reopened the road Monday afternoon but said the eastbound bike lanes were still closed.

Police have closed off Laurier Avenue between Metcalfe and Elgin streets after a water main broke on Monday afternoon. (Roger Dubois/CBC)

City crews began digging Monday evening to reach the water main and police closed the road in both directions.

Water began gushing from several cracks in the road Monday afternoon after the main broke, and onlookers said the road appeared to heave and buckle as water spewed out.

Sean Harrington, a building manager at 150 Laurier Ave., said he's never seen a water main break like it before.

"I heard a loud bang and felt a shudder through our lobby," said Harrington. "I turned around and see that the road had heaved up some two to three feet and tens of thousands of gallons of water were coming up out of the roadway."

Harrington said Monday afternoon none of the water had seeped into his building's basement. He said cars parked underground were removed as a precaution.

City crews shut down the water late in the afternoon, leaving some nearby buildings without water.

Residents and emergency personnel watched as water flooded Laurier Avenue on Monday afternoon after the water main ruptured. (Alistair Steele/CBC)

The city spokesperson said there were never concerns about the road collapsing, or that evacuations would be required.

A city salt truck arrived Monday evening to preemptively salt the road in anticipation of temperatures dropping overnight.

A flash freeze warning was in effect for the city as temperatures dropped rapidly in the morning. But Environment Canada ended the warning at 3:19 p.m.